I have three TIFFs are below which is belongs to Alaska HI Chart:

First https://drive.google.com/file/d/1KllacOdKNw866doqjMcounsvofpXBgFh/view?usp=sharing

Second https://drive.google.com/file/d/1_Oi8QwIONZ-CXzYRS0Ic-VQPTFAN4u42/view?usp=sharing

third https://drive.google.com/file/d/1BB_DCW59ecSvFESajWoXm5W6Xt0DRbmo/view?usp=sharing


gdalwarp -dstnodata 0.0 -r lanczos -of GTiff -dstalpha -overwrite --optfile test.txt "C:/Users/Nivesh.shastri/Documents/test3alaskahi/delete/merge.tif"

test.txt contains path of TIFF files. After completion of command, generated merge.tif is blank and same with QGIS.

Also getting warning like: band 5: Band 4 was already identified as alpha band, and band 5 is now marked as alpha too

My primary goal is to merge all TIFF into one TIFF then Translate it to MBTiles using -projwin parameter.

1 Answer 1


In gdalwarp -dstalphais used for adding an alpha band https://gdal.org/programs/gdalwarp.html#cmdoption-gdalwarp-dstalpha


Create an output alpha band to identify nodata (unset/transparent) pixels.

Because your source images already have an alpha band there is no need for -dstalpha. This command runs without errors.

gdalwarp -dstnodata 0.0 -r lanczos -of GTiff test1_translate.tif test2_translate.tif test3_translate.tif merge.tif
Creating output file that is 78105P x 29032L.
Using band 4 of destination image as alpha.
Processing test1_translate.tif [1/3] : 0Using band 4 of source image as alpha.
Using internal nodata values (e.g. 0) for image test1_translate.tif.
...10...20...30...40...50...60...70...80...90...100 - done.
Processing test2_translate.tif [2/3] : 0Using band 4 of source image as alpha.
Using internal nodata values (e.g. 0) for image test2_translate.tif.
...10...20...30...40...50...60...70...80...90...100 - done.
Processing test3_translate.tif [3/3] : 0Using band 4 of source image as alpha.
Using internal nodata values (e.g. 0) for image test3_translate.tif.
...10...20...30...40...50...60...70...80...90...100 - done.
  • First of all ty for your answer, as per your suggestion I have removed <-dstalpha>, TIFFs has been merge successfully. But while translating <gdal_translate -of MBTiles -projwin -207.4014861258131361 74.1710011162752068 -119.4373264976983933 41.4743045882241574 C:\Users\admin\Downloads\gdal\merge.tif C:\Users\admin\Downloads\gdal\transalte.mbtiles> it stuck at 0% and its been 4 hours but didn't completed yet any suggestions? imgur.com/a/fzF3eTS Commented Aug 5, 2022 at 11:46
  • It took 20 minutes for me gdal_translate -of MBTiles -projwin -207.4014861258131361 74.1710011162752068 -119.4373264976983933 41.47430458822 merge.tif merge.mbtiles Input file size is 78105, 29032 0...10...20...30...40...50...60...70...80...90...100 - done. GDAL 3.5.0 on Windows with the binaries from gisinternals.com.
    – user30184
    Commented Aug 5, 2022 at 13:43
  • I am getting warning like Invalid value for 'bounds' metadata. Ignoring it and fall back to present tile extent while execute command 'gdaladdo --config COMPRESS_OVERVIEW LZW -r nearest translate.mbtiles' for generated mbtiles using translate. Any suggestion for this? Commented Aug 8, 2022 at 4:52
  • It is just a warning and GDAL tries to use a reasonable fall back . Do you have problems with the result?
    – user30184
    Commented Aug 8, 2022 at 6:15
  • yes MBTiles not showing on map, I am using mousebird-consulting-inc.github.io/WhirlyGlobe in IPad. Let me try once again whole process Commented Aug 8, 2022 at 7:08

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